1. Field of the Invention
The present invention relates generally to a versatile short circuit protector/controller circuit for drivers and amplifiers, and more particularly pertains to a circuit of the aforementioned type which is extremely versatile in terms of its applicability to different drivers and amplifiers, which has minimal power drain, and which is capable of operation either alone or in an interface with an associated processor, such as a microprocessor.
2. Discussion of the Prior Art
Amplifiers are used extensively in the electronics industry, particularly in instrumentation and automatic test equipment where they form an essential functional block of an overall system. Moreover, it is well known in the art to provide the amplifiers with associated short circuit protection circuits for the protection of the amplifiers, and many of these short circuit protection circuits are designed and constructed integrally with the amplifier in a single integrated circuit or on a single board, which often results in restricted design deficiencies thereof. In order to improve the performance and reliability of the system, while providing testability features and reducing system costs, the design deficiencies of many known prior art short circuit protection circuits should be remedied.
Prior art techniques for protecting amplifiers which are designed and constructed internal to the device generally have associated therewith the following design deficiencies: dissipation of large power under a short circuit condition; requirement for a large heat sink to dissipate excessive heat, which occupies an appreciable usable circuit area; inability to notify a host processor of a short circuit condition when the amplifier is used in a system with processing capability; the short circuit current limit is fixed and can only be changed by redesigning the amplifier (in these systems, the sensing of the current and the processing of the signal is accomplished internal to the amplifier and accordingly critical circuit parameters cannot be changed); because of the continuous generation of heat under short circuit conditions (due to excessive power drain), the temperatures of the junctions within the device increase substantially and adversely affect the operation of the device, even after the short circuit has been identified and rectified; under a short circuit condition, the large current drawn from the power supply generates excessive heat within the system, creating associated cooling problems, and finally, a more costly power supply must be provided for the larger current capability.